Implantable device-related infection (DRI) is a serious problem that arises in about 2% of de novo implants of implantable cardioverter defibrillators (ICDs), and pacemakers. The incidence is higher for patients that are diabetic, on kidney dialysis, receiving device replacements, and undergoing lead revisions. In addition, anecdotal evidence suggests that DRIs are increasing due to growth in device complexity and are more prevalent when implanting physicians are less experienced. Similar DRI rates also occur for other types of medical device implants, including, for example, orthopedic implants, stents, catheters, etc.
A DRI is extremely costly with combined medical and surgical treatment for a DRI ranging from $25,000 to $50,000. Also, a DRI makes the patient susceptible to potentially fatal complications.
The time course of infection development is not fully understood and varies greatly. However, it has been reported that about 30 percent of infections arise less than one month post-implant, another 35 percent occur between one month and twelve months post-implant, and the remainder appear more than a year post-implant.
There is a dearth of technologies available to prevent implantable DRIs. One known product that is commercially available is the AIGISRx AntiBacterial Envelope, which is manufactured by TyRx Pharma, Inc. This antimicrobial pouch, designed for use with pacemakers and ICDs, is a polypropylene mesh that is shaped into a pocket and is impregnated with antibiotics. The pacemaker or ICD is placed into the AIGISRx and the covered device is subsequently implanted. The antibiotics (minocycline and rifampin) are eluted over a minimum period of 7 days in order to prevent DRIs. There are several shortcomings to this approach. First, the approach requires the implanting physician to execute an extra step of placing the pouch over the device. Second, the pouch adds bulk to the implant, which increases patient discomfort post-surgery. Third, device replacement or explant is more difficult due to growth of tissue into the mesh. Finally, the antibiotics only act for a short period of time and, as a result, do not address long-term DRIs.
There is a need in the art for a solution to both short-term and long-term DR's that overcomes all of the above-mentioned issues.